ScreenSaver and KDE Plasma 4.8?

[Martin Gräßlin]

Hi all,

the work on the new screen locker implementation is nearly done (I can unlock again :-) and that brings me to an issue 
where I wanted to have more opinions: screensaver.

What's important to see: screen locker and screen saver are two different things mixed together for historic reasons. 
The screen locker implements the security aspect of preventing someone else to use the screen. The screen saver 
shows an animation so that the hardware is not damaged. For some reasons those two things come together and 
also the old implementation is together.

The new implementation is about screen locking and not saving. My idea is to improve the screen locking experience 
which kind of looks like 1995. Let's reuse the background of the splash screen and show a nice QML-ified dialog for 
unlocking. Instead of showing the unlock dialog only when someone moves the mouse, it would always be present. If 
the screen has been locked for long time DPMS kicks in and disables the screen (yeah for energy saving).

This means there is no more place for screen savers. It would just not be visible. This also means we don't have the 
Plasma Screensaver any more (this might be fixable by using a Plasma containment as the screen locker in the first 
place).

But when compositing is turned off, you currently get the plain old implementation including screen savers. And I don't 
want to change that code.

So there are some solutions:
* drop screensaver support altogether, probably would create some troubles as evil KDE removed screensavers
* add Plasma widget support to new screen locker implementation but drop screensaver support (same problems as 
first option)
* add a fallback to legacy mode if a screen saver is configured. Means same security problems are present again 
which were the reason for moving the screen locker to KWin in the first place

Personally I would prefer option 1 with a later implementation of option 2 (if time allows even for 4.8). Option 2 needs 
support from Plasma hackers who are all currently fixing up a tablet ;-)

A possible solution for the user issue could be to clearly advertise that security reasons are responsible for removing 
screensaver support. Also an improved login process I have in my mind: with only one user configured do not stop at 
KDM but log in directly with screen locked. The unlock dialog would then be shown after the complete session has 
been loaded, so instant usage after typing in the password.

So looking forward to your comments on the subject.

Cheers
Martin
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: This is a digitally signed message part.
URL: <http://mail.kde.org/pipermail/plasma-devel/attachments/20110929/0601334f/attachment.sig>